Reinforced carton



REINFORCED CARTON Filed June 17, 1966 2 Sheets-Sheet 1 'I' l /6 20 I6 320 /6 20 /6 Thomas M. W/'/s0n,ZZT

ATTORNEY INVENTOR Dec. 26, 1967 M. WILSON m REINFORCED CARTON 2Sheets-Sheet Filed June 17, 1966 INVENTOR Thomas M. I W/'/s0n,1ZZ

BY Maw u W ATTORNEY United States Patent 3,360,181 REINFORCED CARTONThomas M. Wilson III, Western Run Road, Cockeysville, Md. 21030 FiledJune 17, 1966, Ser. No. 558,415 Claims. (Cl. 229-37) This inventionrelates generally to folded blank boxes, and more particularly itpertains to double strength cardboard cartons.

Wherever nails, wood screws, bolts or the like are to be packaged, it isdesirable to use extra strength cartons. Since in stock and in shipmentit is expected such heavy articles will be stacked one upon the other, asingle-ply wall is of insuflicient strength.

Up to the present time, the practice has been to use an overlappedconstruction of two pieces, thus requiring two blanks. Another industrypractice employs a zig-zag fold giving a three-ply side wall from asingle blank. The disadvantage of the two blank construction isobviously the extra handling required and the difiiculty of gettingcorrect register of the creasing and slits prior to the gluing operationto result in a single thickness top and bottom flaps and doublethickness side wall.

The zig-zag fold is not applicable to a two-ply side wall although ithas a great advantage in automatic register with its single blank, but,of course, is a costly, unduly thick and heavy carton, three-ply wheretwo-ply would suffice and must be glued on two sides.

Both prior styles of reinforced cartons as well as unreinforced typesare subject to a tendency to be crooked at manufacturers joint or tohave what is known in the industry as points. This is due to lack ofkeying of the flap to the sides.

Accordingly, it is an object of this invention to provide a two-plycarton which is fabricated from a single blank for more economical,accurate fabrication with none of the prior disadvantages.

Another object of this invention is to provide a carton blank havinglittle waste material which when folded is self registering as tocreasing and slits and results in a carton with a strong keyed-togetherflap and side wall to avoid pointing effect.

Still another object of this invention is to provide a folded one pieceblank reinforced wall carton which requires gluing on one side only.

Other objects and attendant advantages of the invention will become morereadily apparent and understood from the following detailedspecification and accompanying drawings in which:

FIG. 1 is a perspective drawing showing the completely assembled cartonincorporating features of this invention;

FIG. 2 is a view illustrating the blank for the carton of FIG. 1;

FIG. 3 is an enlarged detail cross section taken on line 33 of FIG. 2;

FIG. 4 illustrates in perspective the initial stage in overlapping theblank of FIG. 2 to form a carton;

FIG. 5 is a section taken on line 55 of FIG. 4;

FIG 6 is a perspective view showing a later stage in the folding of thecarton blank to form the carton of FIG. 1; and

FIG. 7 is a cross section of a portion of a two ply carton constructedof corrugated material.

Referring now to the details of the invention, the carton 10 shown inFIG. 1 is formed from a one-piece blank 12 cut from suitable sheetmaterial such as cardboard or corrugated board as illustrated in FIG. 2.The blank 12 has longitudinal scores or creases 14 which guide the folding of the closure flaps 16 for the carton when it is to be erected.Transverse scores or creases 18 with slots 20 extended, therebeyond arefor folding the side panels 30 and more completely define the closureflaps 16.

A side stitching or glue flap 22 is formed on one end of the blank 12 bynotching the corners away down to the longitudinal score lines 14. Theblank 12 is slit on its approximate longitudinal center line atreference 24 terminating short of both ends a distance equal to thewidth of the glue flap 22 where transverse slits 26 approximately onehalf the depth of the finished carton in length extend oppositely atright angles.

From the ends of each transverse slit 26, 28 and 29, respecitvely,extend to the adjacent end of the blank 12 and, in the case ofcorrugated'paper, these creases 28, 29 may be slit-scored or perforatedfor suitable hinging depending on the thickness of such material.

Thus, the blank 12 provides an inner wall 32 and an outer wall 34 tomake up the two plies of the completed side panels 30. A layer of glue36 is now applied to the inner face of wall 34. The walls 32 and 34 arenext brought into contact by lifting the lower half of the blank 12 andsuperimposing it upon the other, hinging taking place at the creases 28and 29 as best shown in FIGS. 4 and 5. This operation forms an extrathickness key step 37 both on the glue flap 22 as well as on theopposite end of the now partially folded blank 12.

The carton 10 is completed (in the flat) by bringing the glue flap end22 and the opposite end 38 proximate by folding on adjacent transversescores 18 so as to meet over the central transverse score 18. The keysteps 37 will then interlock to accurately position the flap 22 forstitching or gluing to opposite end 38 without danger of accidentalmisregister.

If this seam thus formed is too thick because of the thickness ofcorrugated paper used, it is possible to first compress the blank 12 atthe hatched areas shown in FIG. 2 by crushing the material as shown inFIG. 3.

The carton 10 is erected for use in the usual manner by expanding thefour side panels 30 and folding in the bottom and top closure flaps 16as shown in FIG. 1.

If desired, the carton 40 can be constructed of corrugated material,such as corrugated fiberboard as shown in FIG. 7. The superimposition ofthe flutes in the twoply side sections 42 and 44 of the carton 40 is, bydesign and construction, more suitable to creasing or scoring for theforming of accurate folded corners than any other possible flutearrangement. The upper and lower superimposed flute arrangement of thetwo-ply side sections 42 and 44 allow the flutes to react in acomplementary fashion under the stress of folding as shown in FIG. 7.

Obviously many modifications and variations of the present invention arepossible in light of the above teachings, It is, therefore, to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. In a carton comprising panels, one of said panels having a side flapoverlapping another of said panels for securement thereto to form saidpanels into the sides of said carton, and top flaps and bottom flapsextending from said panels for forming the top and bottom closures,respectively, of said carton, the improvement comprising said panelsbeing of two-ply material and said top and bottom flaps being ofsingle-ply material, with said side flap having a single-ply portion anda multi-ply portion to form a first key step and with said another ofsaid panels having a single-ply portion and a multi-ply portion to forma second key step which is complementary to said first key step.

2. The improved carton of claim 1 formed from a single carton blank.

3. The carton blank of claim 2 having a pair of longitudinal creases fordividing said blank into a top flap porfolding creases tion, a panelportion, and a bottom flap portion, a longitudinal slit extendingsubstantially midway between said longitudinal creases and terminatingsubstantially the width of said first and second key step short of theends of said blank for dividing said panel ortion into an outer panelportion and an inner panel portion, transverse creases in each saidpanel portion to form said panels, said transverse creases terminatinginto slots in said top flap portion and said bottom flap portion to formthe flaps in each said portion, a first transverse slit extending fromone end of said longitudinal slit and terminating short of one saidlongitudinal creases, a second transverse slit extending oppositely fromthe other end of said longit-udinal slit and terminating a complementarydistance short of the other of said longitudinal creases, andlongitudinal creases extending from each end of each said transverseslits to the corresponding ends of said blank, whereby said inner panelportion can be shifted over on top of said outer panel portion to formsaid panels of twoply material, with said top and bottom flaps remainingsingle-ply material.

of a single-ply of material.

References Cited UNITED STATES PATENTS 2,324,757 7/1943 Botley 229372,344,999 3/1944 Newsorn 22937 XR 3,114,494 12/1963 VVashyluka 229373,189,249 6/1965 Fallert 22937 3,190,533 6/1965 Larson 229--37 XR3,190,535 6/1965 Nute 22937 DAVIS T. MOORHEAD, Primary Examiner.

1. IN A CARTON COMPRISING PANELS, ONE OF SAID PANELS HAVING A SIDE FLAPOVERLAPPING ANOTHER OF SAID PANELS FOR SECUREMENT THERETO TO FORM SAIDPANELS INTO THE SIDES OF SAID CARTON, AND TOP FLAPS AND BOTTOM FLAPSEXTENDING FROM SAID PANELS FOR FORMING THE TOP AND BOTTOM CLOSURES,RESPECTIVELY, OF SAID CARTON, THE IMPROVEMENT COMPRISING SAID PANELSBEING OF TWO-PLY MATERIAL AND SAID TOP AND BOTTOM FLAPS BEING OFSINGLE-PLY MATERIAL, WITH SAID SIDE FLAP HAVING A SINGLE-PLY PORTION ANDMULTI-PLY PORTION TO FORM A FIRST KEY STEP AND WITH SAID ANOTHER OF SAIDPANELS HAVING A SINGLE-PLY PORTION AND A MULTI-PLY PORTION TO FORM ASECOND KEY STEP WHICH IS COMPLEMENTARY TO SAID FIRST KEY STEP.